U.S. patent number 5,941,480 [Application Number 08/852,870] was granted by the patent office on 1999-08-24 for hinge line skin system for an aircraft.
This patent grant is currently assigned to McDonnell Douglas. Invention is credited to Robert Henry Wille.
United States Patent |
5,941,480 |
Wille |
August 24, 1999 |
Hinge line skin system for an aircraft
Abstract
A hinge line system (52) for an aircraft has a structural block
(22) attached to a first edge of a hinge line. The structural block
(22) has a flange (28) attached to a first end of an elastic sheet
(32). A second structural block (24) is attached to a second edge
of the hinge line. The second structural block (24) has a second
flange (30) attached to a second end of the elastic sheet (32).
Inventors: |
Wille; Robert Henry (St.
Charles, MO) |
Assignee: |
McDonnell Douglas
(N/A)
|
Family
ID: |
25314452 |
Appl.
No.: |
08/852,870 |
Filed: |
May 8, 1997 |
Current U.S.
Class: |
244/131; 244/133;
244/213; 244/219; 244/123.1 |
Current CPC
Class: |
B64C
3/48 (20130101); B64C 9/02 (20130101); Y02T
50/30 (20130101); Y02T 50/10 (20130101) |
Current International
Class: |
B64C
9/00 (20060101); B64C 9/02 (20060101); B64C
3/48 (20060101); B64C 3/00 (20060101); B64C
001/06 (); B64C 003/58 () |
Field of
Search: |
;244/213,214,215,219,123,130,131,132,133 ;442/104,105,306,318 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Jordan; Charles T.
Assistant Examiner: Wesson; Theresa M.
Attorney, Agent or Firm: Halling; Dale B.
Claims
What is claimed is:
1. A hinge line sock system for an aircraft, comprising:
a first stretchable knit fabric;
a uniform elastomer skin having a top surface bonded to the
stretchable knit fabric;
a second stretchable knit fabric bonded to a bottom surface of the
elastomer skin;
a first rigid structural member attached to a first end of the
elastomer skin, the first rigid structural member attached to a
control surface of the aircraft and having a shear bonding area;
and
a second rigid structural member attached to a first end of the
elastomer skin, attached to a structural member of the
aircraft.
2. The hinge line sock system of claim 1, further including an
environmental coating covering the first stretchable knit
fabric.
3. The hinge line sock system of claim 1, further including a sill
attached to the structural member of the aircraft and adjacent to
the second stretchable knit fabric the sill supporting the second
stretchable knit fabric when the control surface is pivoted.
4. The hinge line sock system of claim 1, wherein the first
stretchable knit fabric has a plurality of elastic fibers.
5. The hinge line sock system of claim 1, wherein the first
stretchable knit fabric is coated with an electrically conductive
material.
6. The hinge line sock system of claim 5, wherein the elastomer
skin is in an extended state throughout a majority of a range of
motion of the hinge line.
7. A hinge line system for an aircraft comprising:
a structural block attached to a control surface of the aircraft,
the structural block having a flange;
a first stretchable knit fabric;
an elastic sheet having a first end attached to the flange of the
structural block, the elastic sheet having a top surface bonded to
the stretchable knit fabric;
a second stretchable knit fabric bonded to a bottom surface of the
elastic sheet; and
a second structural block attached to a structural member of the
aircraft, the second structural block having a second flange
attached to a second end of the elastic sheet.
8. The hinge line system of claim 7, further including a support
sill connected to the first edge of the hinge line and adjacent to
a surface of the elastic sheet.
9. The hinge line system of claim 8, further including an
environmental coating covering the first stretchable knit
fabric.
10. The hinge line system of claim 8, wherein the first stretchable
knit fabric is coated with a conductive material.
11. The hinge line system of claim 8, wherein the first stretchable
knit fabric has a plurality of elastic fibers.
12. The hinge line system of claim 7, wherein the elastic sheet is
in an extended position throughout an operating range of motion of
the control surface.
13. A hinge line skin for an aircraft, comprising:
a first rigid member attached to a control surface of the aircraft,
the rigid member having a shear bonding area;
a stretchable knit fabric;
an elastic panel having a first end bonded to the shear bonding
area, the elastic panel having a top surface bonded to the
stretchable knit fabric;
a second stretchable knit fabric bonded to a bottom surface of the
elastomer sheet; and
a second rigid member attached to a structural member of the
aircraft, the second rigid member having a second shear bonding
area bonded to a second end of the elastic panel.
14. The hinge line skin of claim 13, further including a support
sill attached to the structural member.
15. The hinge line skin of claims 13, wherein the elastic panel has
an applied tension.
Description
FIELD OF THE INVENTION
The present invention relates generally to aircraft and more
particularly to a hinge line skin system for an aircraft.
BACKGROUND OF THE INVENTION
All aircraft employ control devices on the wings, tails or
fuselages. These control devices include ailerons, leading edge
flaps, rudders and elevators to name a few. All these control
devices have hinge lines, that if not aerodynamically sealed result
in aerodynamic spillage. Aerodynamic spillage occurs when air
passes from the high pressure side of a control surface to the low
pressure side. Typically this occurs along the hinge line of the
control surface. Aerodynamic spillage results in a less efficient
control device. Other door hinges, such as those used for avionics
bays, also result in aerodynamic drag that reduces the aircraft's
performance.
Thus there exists a need for a hinge line seal for control surfaces
of an aircraft and other hinged doors that eliminates (or reduces)
aerodynamic spillage and is lightweight.
SUMMARY OF THE INVENTION
A hinge line system for an aircraft that overcomes these and other
problems has a structural block attached to a first edge of a hinge
line. The structural block has a flange attached to a first end of
an elastic sheet. A second structural block is attached to a second
edge of the hinge line. The second structural block has a second
flange attached to a second end of the elastic sheet.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an aircraft;
FIG. 2 is a perspective view of a cutaway drawing of a hinge line
skin panel;
FIG. 3 is a cross sectional view of an aircraft control surface
having a hinge line skin system; and
FIG. 4 is a cross sectional view of the aircraft control surface of
FIG. 3 in a tilted position.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an aircraft 10. The aircraft has a
number of control surfaces 12-18 that have hinge lines that can
allow aerodynamic spillage. The hinge lines of the control surfaces
12-18 require a seal to prevent the aerodynamic spillage.
The key to providing such a seal is a hinge line skin 20 shown in
FIG. 2. The hinge line skin 20 has a rigid member (first rigid
structural member) 22 and a second rigid member (second rigid
structural member) 24 that are attached to opposite edges of a
hinge line. Attachment provisions 26 such as counter sunk screw
holes, are provided in the rigid member 22 and the second rigid
member 24. The rigid member 22 has a shear bonding area (flange,
shear joint) 28. Similarly, the second rigid member 24 has a second
shear bonding area (second flange) 30. An elastic panel 32 has a
first end 33 that is bonded to the shear bonding area 28 of the
rigid member 22. A second end is bonded to the second shear bonding
area 30. The shear bonding area 28, 30 of the rigid members 22, 24
enhances the strength of the bond between the rigid member 22, 24
and the elastic panel 32. This results from the fact that adhesives
have higher shear strength than lateral (perpendicular to the plane
of the adhesive) strength.
The elastic panel 32 in one embodiment is an elastomeric material
such as silicone. In another embodiment, the elastic panel 32
comprises an elastomer skin 34 with a stretchable knit fabric 36
bonded to a top surface of the elastomer skin 34. A second
stretchable knit fabric (second knit fabric) 38 is bonded to a
bottom surface of the elastomer skin 34. In one embodiment, the
stretchable knit fabric 36, 38 has a plurality of SPANDEX.RTM.
fibers. In another embodiment, the stretchable knit fabric 36, 38
is coated with an electrically conductive material (conductive
material), such as a metal. The addition of the electrically
conductive material provides an electromagnetic interference (EMI)
shield. EMI shielding can protect electronic instruments contained
in the wings or other aircraft parts to which the control surface
is attached.
In yet another embodiment, an environmental coating 40 is placed
over the stretchable knit fabric (knit fabric) 36, 38. The
environmental coating in one embodiment is an elastomeric coating
that can be made from fluorosilicones, fluoroelastomers, silicones,
thermoplastic elastomers, urethanes or other viable elastic
materials. The environmental coating 40 protects the elastomer skin
34 from jet fuel, oil and other solvents.
FIG. 3 shows a cross section of a control surface 50 pivotally
attached to a structural member 51 of an aircraft. A hinge line
system (hinge line sock system) 52 is used to cover gaps resulting
along the hinge line. The hinge line system 52 includes the hinge
line skin 20. The hinge line skin 20 is attached so that in the
position shown in FIG. 3 the elastic panel 32 is in an extended
state. One method of accomplishing this is to pivot the control
surface 50 beyond its standard operating range when installing the
elastic panel 32 (as shown in FIG. 4). As a result the elastic
panel 32 will be in the extended state (applied tension) through
out the operating range (majority of a range of motion) of the
control surface 50. By stretching the elastic panel 32 it has
lateral stability to pressure variations. Since the elastic panel
32 is extended (an extended position) throughout the operating
range (normal range of motion), it will have lateral stability
throughout the operating range of the control surface 50.
A pair of sills (support sill) 54 is provided under the hinge line
skin (adjacent to a surface of the elastic sheet) 20. The sill 54
provides support for and shape the elastic panel 32 when the
control surface 50 is pivoted. The ends of the sills 54 are curved
to provide a smooth curvilinear shape to the elastic panel 32.
Thus there has been described a hinge line system for an aircraft
that prevents aerodynamic spillage and is light weight. While the
invention has been described in conjunction with specific
embodiments thereof, it is evident that many alterations,
modifications, and variations will be apparent to those skilled in
the art in light of the foregoing description. Accordingly, it is
intended to embrace all such alterations, modifications, and
variations in the appended claims.
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